Input validation error in Rsync - CVE-2026-53798
Published: August 13, 2026
Vulnerability identifier: #VU142292
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-53798
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to modify file ownership metadata.
The vulnerability exists due to improper input validation in the rsync daemon name-converter handling logic when processing an empty converter response for an unknown sender name. A remote attacker can provide an unknown name that causes an empty response to be treated as success and mapped to uid/gid 0 to modify file ownership metadata.
Only configurations with fake super = yes are affected.
Affected software
Rsync
How to mitigate CVE-2026-53798
Install security update from vendor's website.
Rsync - update to 3.5.0